8213509 has 4 divisors (see below), whose sum is σ = 8242816. Its totient is φ = 8184204.

The previous prime is 8213503. The next prime is 8213531. The reversal of 8213509 is 9053128.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 8213509 - 2¹¹ = 8211461 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8213503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14229 + ... + 14794.

It is an arithmetic number, because the mean of its divisors is an integer number (2060704).

Almost surely, 2^8213509 is an apocalyptic number.

It is an amenable number.

8213509 is a deficient number, since it is larger than the sum of its proper divisors (29307).

8213509 is a wasteful number, since it uses less digits than its factorization.

8213509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29306.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 8213509 is about 2865.9220156871. The cubic root of 8213509 is about 201.7636437560.

The spelling of 8213509 in words is "eight million, two hundred thirteen thousand, five hundred nine".